An unemployed man killed a millionaire's daughter after their relationship ended because she threatened to go out with someone else, a court heard yesterday.

Jurors at Hull crown court were told that Roger Holtby, 38, strangled Suzy Healey, daughter of the Hygena kitchen mogul Malcolm Healey, at her home, Ellerker Hall, in East Yorkshire, in August 2005. Holtby, who was known to his friends as George, killed Miss Healey before driving in a drunken state to a friend's home where he spent the night, the court heard. The next day he disposed of his jeans in a field and drove to Whitby in North Yorkshire where he was arrested later that morning.

Holtby denies murder but admits manslaughter.

The court heard that the couple had been in an on-off relationship for nine months.

Holtby had moved into Ellerker Hall in March 2005 and although he moved out three months later the couple continued seeing each other. James Goss QC, prosecuting, said: "Their relationship was marred by regular arguments and fallings out. One of the sources of argument was the defendant's not working. She thought he was lazy and didn't want him living off her. She also didn't like his controlling behaviour."

The relationship deteriorated when Miss Healey decided that it was over with Holtby and went on holiday without him.

On her return from holiday she celebrated her forthcoming birthday, but did not invite Holtby.

Despite the increasing distance between them, Miss Healey agreed to see Holtby at Ellerker Hall and he arrived at about 5.30pm on August 21. Mr Goss said: "Suzy Healey was never seen alive again."

He told the court that Holtby drove Miss Healey's pick-up to a garage at about 10pm, where he bought a bottle of whisky and a two-litre bottle of cider before calling his friend Michael Naylor and saying he thought he had done something terrible.

Mr Goss said: "He said he thought he might have strangled Suzy, saying they had spoken earlier and she had been threatening to go out with someone else."

Mr Naylor thought Holtby was exaggerating and put his friend to bed. However, Mr Naylor and his girlfriend became concerned when they were unable to contact Miss Healey and called the police.

Holtby, Mr Goss continued, also phoned another friend, Trevor Harrison, a gardener at Ellerker Hall. He is said to have told Mr Harrison: "She's dead and it's finished."

He also said that he had nothing more to live for, that he had stopped her, destroyed her and was now going to stop himself.

Holtby was driving towards Whitby when he was in a collision with other cars and was arrested when found slumped drunk over the steering wheel.

Giving evidence on the opening day of the trial, Dr Kenneth Shorrock, the consultant Home Office pathologist who carried out the postmortem examination, told the jury that Miss Healey died from manual strangulation.

He added that there was "more bruising than I'd see in the majority of cases of strangulation" and "sustained and unremitting pressure" would have had to have been applied for about 30 seconds.

He also told the court that Miss Healey had 244mg of alcohol in 100ml of her blood. The legal drink-drive limit is 80mg.

The court heard that Miss Healey had the "good fortune" to be a member of an "extremely wealthy" family.

Her father owes much of his £740m fortune to the sale of his Hygena kitchen business. He lives on an estate about 10 miles from Ellerker Hall.

His brother Eddie, also a multimillionaire, and developer Paul Sykes turned a site outside Sheffield into the Meadowhall shopping centre, which was sold seven years ago for £1.17bn.